Researchers in Sweden have a new blood test that could give doctors and athletic trainers a better idea of when an athlete can return to the field, court or ice following a concussion.
Researchers from the University of Gothenburg have developed a high-sensitive blood test that can show when athletes are safe to return to the playing field following a concussion, after identifying a superior blood-based biomarker for assessing subtle brain injuries.
“This could serve as an objective test a long side clinical evaluation to whether a player is fit to return to playing,” Pashtun Shahim, PhD, lead author of the article, said in a statement. “Currently, we lack an objective test like this.”
The researchers looked at 288 men’s ice hockey players that played in the Sweden’s highest division between 2012 and 2015.
“All of the involved team physicians and medical staff have been very helpful with conducting this study,” Shahim said. “Without them we would have not been able to conduct a study of this kind and magnitude across Sweden. It has been a massive undertaking.”
In total, 105 players suffered a concussion during the study period, with blood samples taken from 87 players one, 12, 36 and 144 hours following the concussion, enabling the researchers to compare concentrations in the blood of known biomarkers for concussions. A fifth sample was taken at the time when the person was determined fit to return to unrestricted competition.
The researchers found that the levels of the protein neurofilmanet light (NfL) had the clearest connection to the severity of concussion, measured by the number of days it took for the player to return to the ice.
“The strength of this study is that we longitudinally followed how these biomarkers are released and cleared from the blood,” Shahim said. “What we observed was that NfL was released within an hour after the concussion, and then it increased over time in players who had prolonged symptoms.”
The researchers also examined the levels of three other biomarkers–tau, S100B and neuron-specific enolase—which all decreased quickly and were unable to be used to see how injured the players were after seven to 10 days.
“Currently the duration of players’ symptoms determines when it is safe to play again,” Shahim said. “The finding that serum NfL concentrations correlate with the duration of post-concussive symptoms or return to play, implicates that serum NfL might serve as an objective test of when it is safe to return to play. It is important to protect the players from developing long-term symptoms by avoiding premature return to play. Suffering additional concussion, especially when the current post-concussion symptoms are not fully resolved might have long-term consequences.
“There is no need for a biomarker in order to make a diagnosis of concussion, it is a clinical diagnosis that is based on the patient’s symptoms,” he added. “What we are really after is a prognostic biomarker that helps the physicians determine which players or patients might be at increased risk of developing persistent post-concussive symptoms, and thereby adjust the level of rest and care for these players.”
The study was published in Neurology.
